Merge branch 'for-3.6/drivers' of git://git.kernel.dk/linux-block

Pull block driver changes from Jens Axboe:

 - Making the plugging support for drivers a bit more sane from Neil.
   This supersedes the plugging change from Shaohua as well.

 - The usual round of drbd updates.

 - Using a tail add instead of a head add in the request completion for
   ndb, making us find the most completed request more quickly.

 - A few floppy changes, getting rid of a duplicated flag and also
   running the floppy init async (since it takes forever in boot terms)
   from Andi.

* 'for-3.6/drivers' of git://git.kernel.dk/linux-block:
  floppy: remove duplicated flag FD_RAW_NEED_DISK
  blk: pass from_schedule to non-request unplug functions.
  block: stack unplug
  blk: centralize non-request unplug handling.
  md: remove plug_cnt feature of plugging.
  block/nbd: micro-optimization in nbd request completion
  drbd: announce FLUSH/FUA capability to upper layers
  drbd: fix max_bio_size to be unsigned
  drbd: flush drbd work queue before invalidate/invalidate remote
  drbd: fix potential access after free
  drbd: call local-io-error handler early
  drbd: do not reset rs_pending_cnt too early
  drbd: reset congestion information before reporting it in /proc/drbd
  drbd: report congestion if we are waiting for some userland callback
  drbd: differentiate between normal and forced detach
  drbd: cleanup, remove two unused global flags
  floppy: Run floppy initialization asynchronous

19 files changed, 238 insertions, 177 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index dd134d834d58..4b4dbdfbca89 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2909,23 +2909,47 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth,
 
 }
 
-static void flush_plug_callbacks(struct blk_plug *plug)
+static void flush_plug_callbacks(struct blk_plug *plug, bool from_schedule)
 {
         LIST_HEAD(callbacks);
 
-        if (list_empty(&plug->cb_list))
-                return;
-
-        list_splice_init(&plug->cb_list, &callbacks);
+        while (!list_empty(&plug->cb_list)) {
+                list_splice_init(&plug->cb_list, &callbacks);
 
-        while (!list_empty(&callbacks)) {
-                struct blk_plug_cb *cb = list_first_entry(&callbacks,
+                while (!list_empty(&callbacks)) {
+                        struct blk_plug_cb *cb = list_first_entry(&callbacks,
                                                           struct blk_plug_cb,
                                                           list);
-                list_del(&cb->list);
-                cb->callback(cb);
+                        list_del(&cb->list);
+                        cb->callback(cb, from_schedule);
+                }
+        }
+}
+
+struct blk_plug_cb *blk_check_plugged(blk_plug_cb_fn unplug, void *data,
+                                      int size)
+{
+        struct blk_plug *plug = current->plug;
+        struct blk_plug_cb *cb;
+
+        if (!plug)
+                return NULL;
+
+        list_for_each_entry(cb, &plug->cb_list, list)
+                if (cb->callback == unplug && cb->data == data)
+                        return cb;
+
+        /* Not currently on the callback list */
+        BUG_ON(size < sizeof(*cb));
+        cb = kzalloc(size, GFP_ATOMIC);
+        if (cb) {
+                cb->data = data;
+                cb->callback = unplug;
+                list_add(&cb->list, &plug->cb_list);
         }
+        return cb;
 }
+EXPORT_SYMBOL(blk_check_plugged);
 
 void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 {
@@ -2937,7 +2961,7 @@ void blk_flush_plug_list(struct blk_plug *plug, bool from_schedule)
 
         BUG_ON(plug->magic != PLUG_MAGIC);
 
-        flush_plug_callbacks(plug);
+        flush_plug_callbacks(plug, from_schedule);
         if (list_empty(&plug->list))
                 return;
 
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index e54e31b02b88..3fbef018ce55 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -411,7 +411,7 @@ w_al_write_transaction(struct drbd_conf *mdev, struct drbd_work *w, int unused)
                 + mdev->ldev->md.al_offset + mdev->al_tr_pos;
 
         if (!drbd_md_sync_page_io(mdev, mdev->ldev, sector, WRITE))
-                drbd_chk_io_error(mdev, 1, true);
+                drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
 
         if (++mdev->al_tr_pos >
             div_ceil(mdev->act_log->nr_elements, AL_EXTENTS_PT))
@@ -876,7 +876,11 @@ int __drbd_set_out_of_sync(struct drbd_conf *mdev, sector_t sector, int size,
         unsigned int enr, count = 0;
         struct lc_element *e;
 
-        if (size <= 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
+        /* this should be an empty REQ_FLUSH */
+        if (size == 0)
+                return 0;
+
+        if (size < 0 || (size & 0x1ff) != 0 || size > DRBD_MAX_BIO_SIZE) {
                 dev_err(DEV, "sector: %llus, size: %d\n",
                         (unsigned long long)sector, size);
                 return 0;
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index fcb956bb4b4c..ba91b408abad 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -1096,7 +1096,7 @@ static int bm_rw(struct drbd_conf *mdev, int rw, unsigned flags, unsigned lazy_w
 
         if (ctx->error) {
                 dev_alert(DEV, "we had at least one MD IO ERROR during bitmap IO\n");
-                drbd_chk_io_error(mdev, 1, true);
+                drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
                 err = -EIO; /* ctx->error ? */
         }
 
@@ -1212,7 +1212,7 @@ int drbd_bm_write_page(struct drbd_conf *mdev, unsigned int idx) __must_hold(loc
         wait_until_done_or_disk_failure(mdev, mdev->ldev, &ctx->done);
 
         if (ctx->error)
-                drbd_chk_io_error(mdev, 1, true);
+                drbd_chk_io_error(mdev, 1, DRBD_META_IO_ERROR);
                 /* that should force detach, so the in memory bitmap will be
                  * gone in a moment as well. */
 
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 02f013a073a7..b2ca143d0053 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -813,7 +813,6 @@ enum {
         SIGNAL_ASENDER,         /* whether asender wants to be interrupted */
         SEND_PING,              /* whether asender should send a ping asap */
 
-        UNPLUG_QUEUED,          /* only relevant with kernel 2.4 */
         UNPLUG_REMOTE,          /* sending a "UnplugRemote" could help */
         MD_DIRTY,               /* current uuids and flags not yet on disk */
         DISCARD_CONCURRENT,     /* Set on one node, cleared on the peer! */
@@ -824,7 +823,6 @@ enum {
         CRASHED_PRIMARY,        /* This node was a crashed primary.
                                  * Gets cleared when the state.conn
                                  * goes into C_CONNECTED state. */
-        NO_BARRIER_SUPP,        /* underlying block device doesn't implement barriers */
         CONSIDER_RESYNC,
 
         MD_NO_FUA,              /* Users wants us to not use FUA/FLUSH on meta data dev */
@@ -834,6 +832,7 @@ enum {
         BITMAP_IO_QUEUED,       /* Started bitmap IO */
         GO_DISKLESS,            /* Disk is being detached, on io-error or admin request. */
         WAS_IO_ERROR,           /* Local disk failed returned IO error */